Reading a wiki page about Hibernate I elaborated some perplexing conclusions:
1) Bidirectionality is reccomended in one-to-many
2) Bidirectionality is optional in many-to-one
3) Bidirectionality is normally present in many-to-many
4) Unidirectionality is reccomended in one-to-one relationships,
using as owner class the one with the primary key of the
relation (not the foreign key).
Are these statements true? Do you have any example to explain why in some cases unidirectionality is reccomended and in others bidirectionality is reccomended instead?
Here's the wiki page (read under "concepts"):